Running Disparity Encoding for DC-Free Chip-to-Chip Links
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Solution Overview
Problem
Existing encoding methods such as 8b/10b, 64b/66b, and 64b/67b encoding methods suffer from reduced transmission efficiency, uncontrolled running disparity, and run length issues, leading to potential decoding inaccuracies and inefficiencies in data transmission between chips.
Innovation Solution
An encoding device and method that scrambles input data, calculates running disparity, and adds a flag to indicate whether the data should be inverted, ensuring controlled running disparity and run length, thereby maintaining transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 8b/10b encoding method is used, then DC-free transmission is achieved, but transmission efficiency is reduced
Solution Approach 1:
The patent changes the encoding parameters by using 64b/66b encoding instead of 8b/10b, and introduces a running disparity control mechanism with inversion flags to achieve DC-free transmission while maintaining higher transmission efficiency through better bandwidth utilization
Solution Approach 2:
The patent segments the data transmission into fixed 64-bit data blocks with 2-bit control fields, organizing the encoding structure to enable efficient processing and DC-free transmission through systematic running disparity management across segmented data units
2Productivity
If 64b/66b encoding method is used, then transmission efficiency is improved, but running disparity is not controlled
Solution Approach 1:
The patent implements a feedback mechanism where the running disparity is calculated based on previous data, and inversion flags are generated to correct disparity accumulation, ensuring DC-free transmission while maintaining 64b/66b encoding efficiency
Solution Approach 2:
The patent performs preliminary calculation of running disparity before encoding, and pre-determines inversion flags based on the calculated disparity values, enabling proactive control of DC balance throughout the transmission process
3Reliability
If 64b/67b encoding method is used, then running disparity is controlled, but run length is deteriorated
Solution Approach 1:
The patent changes the encoding format from 64b/67b to 64b/66b, adjusting the parameter structure to reduce overhead while implementing running disparity control through inversion flags, thereby maintaining both DC-free transmission and acceptable run length characteristics
Data Source
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AI summary
The present technology relates to an encoding device, an encoding method, a decoding device, a decoding method, and a program that enable encoding with high transmission efficiency by controlling a running disparity. The encoding device includes a scrambling unit that scrambles an input data string, a calculation unit that calculates a first running disparity of the data string scrambled by the scrambling unit, a determination unit that determines whether or not to invert the data string scrambled by the scrambling unit on the basis of the first running disparity calculated by the calculation unit and a second running disparity calculated at a time point before the first running disparity, and an addition unit that inverts or non-inverts the data string scrambled by the scrambling unit on the basis of a determination result by the determination unit, adds a flag indicating the determination result, and outputs the data string. The present technology can be applied to devices that perform SLVS-EC standard communication.